Field of Invention
The present invention relates to the field of liquid crystal displays, and more particularly to a pixel array for a liquid crystal display device.
Description of Prior Art
LCD have been developed rapidly due to their small sizes, light weights, and low power consumption. However, in order to make the LCD be applied on large screen displaying and to replace the cathode ray tube (CRT) display, the viewing angle characteristic of the LCD should be improved.
The LCD viewing angle problem is resulted from the operating principle of liquid crystal. A liquid crystal molecule is rod-shaped. Different molecule arrangements correspond with different optical anisotropies. The smaller the angle between the incident light and the liquid crystal molecule is, the smaller the bi-refraction is; on the contrary, the larger the angle between the incident light and the liquid crystal molecule is, the greater the bi-refraction is. The angles between light rays entering a liquid crystal cell at different deviation angles from the normal direction of the display screen and the orientation of the liquid crystal molecules are different. As a result, effective optical path differences (OPD) will be different for different viewing angles. Optimum OPD of the liquid crystal cell is designed according to the normal line, which is perpendicular to the liquid crystal cell. For light rays of oblique angular incidence, when the minimum transmittance increases as the angle increases, and the contrast decreases accordingly. A color shift of an image viewed at a large viewing angle is a main drawback of the existing LCD.
In order to reduce the color shift phenomenon, the essence of the multi-domain vertical alignment (MVA) is to improve the color shift phenomenon by forming domains as much as possible. While two different voltages (one high and one low) control different regions of one sub-pixel at the same time, this is an 8-domain improvement technique. While voltages of two levels control two sub-pixels connected with each other, respectively, this is called two pixel rendering (TPR) technique. The TPR technique can achieve a high transparency feature. However, in order to have a finer resolution of the LCD applying the TPR technique, and charge pixel units more fully, special requirements for the arrangement of the LCD pixel units and the inversion manner of the pixel driving voltage are generated.
So there is a need to provide a pixel array used for an LCD device to overcome the problem stated above.